Fluid coupling



Nav. 3o, 1943'.

W. A. EATON ET AL FLUID COUPLING Filed 0G13. 5, 1941 1.. .wv 7 F a x umm/ @om m a w 1 ze 2 n 9 M 1 l l 1 au 6 6 0 o 4 1 1 Patented Nov. 30,1943 UNITED sTATEs PATENT OFFICE FLUID coUrLlNG Wilfred A. Eaton andRoger H. Casler, Elyria,

Ohio, assignors to Bendix-Westinghouse Automotive Air Brake Company,Elyria, Ohio, a corporation of Delaware Application October 3, 1941,Serial No. 413,512

8 Claims.

This invention relates to braking systems for tractor-trailer vehicletrains and more particularly to means for coupling the braking system ofa tractor vehicle to that of a trailer vehicle.

It; has previously been customary in connection with fluid pressurebrake systems installed on tractor-trailer trains to conduct the supplyof fluid pressure from one vehicle to the other by means of flexiblehose which is connected to at least one of the vehicles by means of areadily detachable coupling, so that, on uncoupling of the vehicles, theoperator could at the same time uncouple the hose. In View of the factthat such hose couplings of the detachable type necessarily have anoutlet port, it has frequently happened that, after the vehicles wereuncoupled, dirt or other foreign substance entered the outlet port ofthe hose coupling and was, on subsequent recoupling of the vehicles,carried through the lines of the trailer by the flow of iiuid pressurefrom the tractor brake system with resultant damage to the control valvemechanisms on the trailer.

It is accordingly an object of the present; invention to provide novelmeans for coupling the fluid pressure control lines of tractor andtrailer vehicles so constituted as to prevent the entrance of dirt orvother foreign substance into the couplings during the time they aredisconnected.

Another object of the invention is to provide closure means for suchcouplings so arranged as to be automatically operated to establish afluid pressure connection between the coupling members when the membersare coupled together.

Yet another object of the invention is to provide a detachable couplingdevice for fluid pressure lines having means for preventing the entranceof dirt to the coupling members when uncoupled and for permitting thepassage of fluid when coupled, this means being actuated both by the actof mechanically locking the coupling members together and by the fluidpressure ex- A isting in the lines attached thereto.

A further object of the invention is to provide novel and efiicient hosecoupling means so constituted as to prevent the entrance of dirt to theinterior of the coupling when the coupling is disconnected withoutacting to prevent the escape of fluid pressure from the coupling in theevent of accidental disconnection of the coupling A still further objectof the invention is to provide dirt excluder means for' detachable hosecouplings in a fluid pressure brake system so constituted as to permitproper operation of the braking system with the couplings in eitherconnected or disconnected position.

Another object is to provide, in a coupling having a fiuid pressureoperated dirt excluder, means for connecting the pressure responsivemember therein with atmosphere and means for automatically preventingthe clogging of said atmospheric connection.

' Yet another object is to provide a coupling of the above type soconstituted as to prevent distortion of the parts with the coupling indisconnected position.

Other novel features of the invention will be more fully understood fromthe following detailed description when taken in connection with theaccompanying drawing. It is to be expressly understood, however, thatsuch drawing is for purposes of illustration only and is not to be takenas a definition of the limits of the invention, reference being hadforsuch purpose to the appended claims.

Referring to the drawing, wherein similar reference numerals refer tolike parts throughout the several views:

Fig. 1 is a, diagrammatic view showing the elements of a tractor-trailerfluid pressure braking system equipped with hose couplings of the typeabovereferred to;

Fig. 2 is a sectional view of one form of the invention;

Fig. 3 is a sectional view of another form of the invention, and

Fig. 4 is a sectional view of a modified form of the inventionillustrated in Fig. 2.

Referring more particularly to Fig. 1 of the drawing, a tractor-trailerfiuid pressure brake system is disclosed therein, wherein a fluidcompressor 4, driven by the vehicle motor or by any other suitablemeans, not shown. is adapted to supply fluid pressure to a tractorvcarried reservoir 5 through the medium of conduit 6 interconnectedtherebetween, the fluid pressure stored in the reservoir being thenceconducted'to the inlet chamber of a brake valve 'l through the medium ofa connecting conduit 8. The brake valve 1 is not illustrated in detailbut is preferably of' the so-called self-lapping type and may beconstructed in accordance with the principles set forth in the patent toW. A. Eaton No. 2,204,530, issued June 11, 1940. yThe tractor vehicle isprovided with rear fluid pressure brake actuators or cylinders 9 andfront brake actuators or cylinders l0, operation of the brake valve 1 bythe vehicle operator serving to connect the conduit 8 with the rearbrake chambers 9 through conduits Il and l2 and with the front brakechambers I0 through conduits I3, I4 and l5 and, on reverse operation, toconnect the brake chambers3 and I with atmosphere to exhaust fluidpressure therefrom and release the brakes in a manner well known tothose skilled in the art. In order that the trailer vehicle may also besupplied with iiuid pressure from the reservoir 5 carried by thetractor,a conduit I8 connected to the reservoir serves to conduct airltoa shut-off valve I1 located at the rear end of the tractor, this lineconsti-tuting what is commonly known as the emergency line to thetrailer. A flexible hose I8 f is connected to the rear of the shut-offvalve `I1 and is adapted to be coupled to an emergency line of thetrailer in a manner hereinafter to be described. In like manner, meansare provided for conducting fluid pressure from the brake valve 1 to thebraking system ofthe trailer by means of a conduit I9 connected to thebrake valve through conduit I3 and provided with a shut-off valvelocated adjacent the rear end of the tractor. A flexible hose 2| servesto connect the valve 20 with the trailer braking system as willhereafter be described.

The trailer braking system includes an emergency reservoir 22, a pair offluid pressure brake actuators or cylinders 23 and a relay emergencyvalve 24 for controlling the degree of fluid pressure in the brakeactuators 23. This latter valve, not shown in detail, is preferablyconstructed in accordance with the principles set forth in the patent toStephen Vorech and Wilfred A. Eaton No. 2,049,984, issued August 4,1936, particular reference being had to Fig. 3 of the drawing thereof.The emergency portion of the valve serves to permit the flow of uidpressure from a trailer emergency line 25 to the trailer reservoir 22through a conduit 26, while the relay portion of the valve serves, undercertain conditions hereinafter to be described, to connect conduit 26with a conduit 21, which latter conduit is connected with the trailerbrake actuators 23 by means oi' conduits 23. The relay portion of therelay emergency valve is adapted to be controlled by uid pressureconducted thereto through a conduit 29, this conduit being connected tothe flexible hose 2I leading from the tractor through the medium of asliut-oif valve 30, a conduit 3| and a coupling device 32 having asection/33 carried by the trailer and a similar section 34 detachabletherefrom and connected with the flexible hose 2 I. In like manner, thetrailer emergency line 25 is connected with the tractor carried hose I3by means of a shut-olf valve 35, a conduit 36 and a coupling device 31having a portion 38 connected with the conduit 33 and a similar portion39 detachable therefrom and connected with the flexible hose I8.

When it is desired to operate` the vehicle, the compressor 4, onstarting of the vehicle engine, serves to supply uid pressure to thereservoir 5 through conduit B, and the trailer reservoir 22 is in turnsupplied with fluid pressure therefrom through conduit I8, valve I1,flexible hose I8, coupling device 31, conduit 3B, valve 35, conduit 25,valve mechanism 24 and conduit 26, while fluid pressure is supplied tothe tractor carried brake valve 1 from the reservoir 5 by means of theconduit 8 as heretofore stated. If it is now j desired to apply thebrakes on the vehicles, actuation of the valve 1 by theoperator servesto supply fluid pressure from the reservoir 5 to`the tractor brakeactuators 3 and I0 through the lconduits heretofore described andlikewise serves to supply fluid pressure for the control of the 'relayemergency valve 24 through the medium of conduits I3 and I 9, valve 20,flexible hose 2i. coupling device 32, conduit 3|, valve 30 and conduit29, it being understood that, on operation of the valve 1 to supply agiven degree of pressure to the actuators 9 and I0 on the tractor, thevalve mechanism 24 on the trailer will likewise beactuated to connectthe trailer emergency reservoir 22 with the trailer brake actuators 28through conduit 23, valve 24 and conduits 21 and 23, the pressuresupplied to the trailer brake actuators 23 from the reservoir 22 beingsubstantially equal to that supplied to the tractor brake actuators 9and I0 from the tractor reservoir 5.

In addition to the normal braking control operation just described, thebraking system illustrated is so constructed as to provide an automaticapplication of the brakes on the trailer on failure of the fluidpress-alare in the emergency line for any reason, and the couplingdevices 32 and 31 are so designed that, in the event of breakaway of thetrailer from the tractor, the two adjacent parts of the coupling willseparate without injuring or breaking the flexible connecting hose. Inthe event this separation of the adjacent parts of the coupling device31 occurs, a reduction of pressure in the conduit 25 occurs which issufficient to actuate the emergency valve and permit the brake actuators23 to be energized by fluid pressure from the reservoir 22 as previouslydescribed.

In view of the foregoing explanation of the operation of the brakingsystem illustrated in Fig.` 1, it will be apparent to those familiarwith the braking art, that separation of the coupling members 38 and 39on break-away of the trailer must necessarily result in a reduction ofpressure in the conduit 25 if proper operation of the trailer brakingsystem is to take place, and, with particular reference to Fig. 2 of thedrawing, means have been provided for preventing the entrance of foreignmatter into the coupling members when they are in a disconnectedposition, without in any way interfering with the above describedemergency operation of the brakes on separation of the coupling members.

The coupling device illustrated in Fig. 2 includes a pair of bodymembers substantially identical in form and adapted, on relativerotative movement thereof, to lock together as more fully described inthe patent to C. C. Farmer No. 1,765,576, issued June 24, 1930. Each ofthe members 50 is provided with a cam surface 5I and a cam surface 52oppositely disposed and adapted, on rotative movement ofthe couplings,

' to move the coupling members toward each other.

'I'he casing 50 is adapted to be connected with the fluid pressure brakesystem through the medium of a conduit 53 connected with a chamber 54formed in the casing, this chamber being provided with an outlet port 55having a resilient tubular gasket 53 suitably retained therein as bymeans of its engagement with a groove 51 formed in the wall of the bore.The gasket projects below a machined face 58 formed on the casing and isadapted, in response to the operation of the cam faces 5I and 52, onrotative movement of the members, to engage the corresponding gasket inthe other member in sealing engagement to prevent the escape of fluidpressure therebetween. The tubular gasket is preferably provided with atapered bore 59 for establishing a connection between the chambers 54 ofthe coupling casings and thisy bore is normally closed by means of a.valve member 30 having a tapered portion BI normally urged into aposition to close to the casing by means of bolts 84.

the tapered bore oi' the gasket by means of a spring 02 interposedbetween theupper enel of the valve member and a cover member 88 clampedA pressure responsive member or diaphragm -85 is clamped between thecasing 50 and the cover member 88 and is attached at its center to thevalve member 88 in sealing engagement therewith by means of suitableflanges 88 formed on the valve member, the diaphragm thus serving, inconnection with the cover member 88, to define a second chamber 81 whichis maintained under atmospheric pressure by virtue of its connectionwith atmosphere through a port 88 formed in the wall of the cover. Inorder that the downward movement of the valve member 80 underthe'iniluence oi' the spring 82 may be limited to prevent unduedistortion of the gasket 58,'the valve member 88 is also provided with astem 89 extending through the bore 88 and provided at its outer end witha head 18, which head is adapted to contact the -outer face of the cover58 and limit the downward travel o'f the valve 88 to a predeterminedamount. In the event the port 68 is clogged with dirt, the valve stem 89acts by virtue of its movement therethrough to loosen the dirt andeliminate this condition.

If a coupling device of the construction Just described is connected,for example, between the flexible hose I8 and the trailer emergencylines 38 and 25 of the brake system shown in Fig. 1, it will be apparentthat the admission of uid-pressure to the chamber 54 from the tractorwill act to move the diaphragm 55 upwardly with the resuit that thevalve member 60 will likewise move upwardly to permit the passage oifluid pressure through the bore of the resilient gasket 58. If thespring 52 in the lower coupling member is properly chosen, the iluidpressure acting on the upper surface of the lower valve member 50 willbe sumcient to move the valve downwardly. against the force of thespring and permit the passage of fluid pressure into the chamber 54 ofthe lower coupling member, whereupon this pressure vwill act on thelower diaphragm member to move the lower valve 50 further downward4 andpermit unobstructed communication between the chambers 54 of the twocoupling members, and the valves will be maintained in open positionuntil such time as the pressure again drops due eitherv to extremeleakage in the system or to disconnection of the couplings. When suchdisconnection occurs, the chamber 54 of the lower coupling' memberconnected to the emergency line of the trailer will remain connected toatmosphere until'the pressure in the chamber drops to a point where thespring is suficient to overcome the air pressure then acting on thediaphragm, whereupon the valve will close in such a manner as to preventthe entrance of dirt and other foreign substance into the chamber 54.while 'the action of the valve in remaining open until the pressure dropoccurs will permit the emergency valve on the trailer to eiect anemergency application of the brakes due to the drop in pressure in theconduit 25. f

In the event the coupling device described in connection With- Fig. 2were to be used in the service line between the tractor and trailer.however, it is apparent that the valve 60 in the portion connected tothe trailer might tend to restrict the flow of iiuid pressure betweenthe tractor and trailer due to the fact that this conduit is only underpressure whenthe brakes are being applied, and further due to the factthat this brake application must take place in the shortest possiblespace of time in order to obtain emcient operation of the brakes. Theconstruction illustrated in Fig. 3 of the drawing, accordingly,contemplates a coupling more particularly adapted for -useinterchangeably in either the emergency line or the service line toprevent the possibility ot this undesirable restriction of fluidpressure flow from occurring. Here again, a casing 50 is provided foreach coupling member having a chamber 54 formed therein and beingprovided with an outlet port 55 carrying a resilient gasket 55 adaptedto engage a correspond- 'ing resilient gasket in the other section ofthe coupling. A spring pressed diaphragm 85 is also clamped between thecasing 50 and a cover Plate 88 mounted on the casing and is attached tothe valve for normally urging the valve toward closed position and foropening the valve under the action of iluid pressure in the mannerheretofore described in connection with the mechanism shown in Fig. 2.In this particular embodiment oi' the invention, however, mechanicalmeans are also provided 'for opening the valve. such means including aplunger 88 slidably mounted for vertical movement in a bore 8| formed inthe casing, the lower end of the plunger being adapted, oninterengagement of the coupling members,` to be moved upwardly by virtueoi' its engagement with a cam surface 82 formed on the other couplingmember, and the upper end engaging a projection 88 on a lever 84pivotally mounted at its left end on the casing by means of a pivot -pin85 and adapted, at the right end, to engage the lower face of the ilange55 formed on the valve 50, which ilange also acts to connect the valvewith the diaphragm as previously described in connection with Fig. 2. Inorder that `leakage of iluid pressure by the plunger may be prevented,grooves 85 are provided on the plunger, resilient gaskets 81 beingcarried by these grooves in sealing engagement with the walls of thebore 8|. Theother member of the coupling device may, if desired. alsohave. the construction just described, and, if this is the case, it willbe apparent that engagement of the coupling members of the device willactuate the correspoending plungers to open the valves through -theconnections described and permit unrestricted communication between thechambers 54 of the coupling members. Thus, if the upper coupling memberhas its chamber 54 connected with the service line of the tractorthrough flexible hose. 2|, and the lower coupling member has its chamber54 connected with the relay emergency valve mechanism 24 of the trailerthrough conduit 3|, valve 30 and conduit 29, it will be apparent thatboth valves will be maintained in open position allowing unimpeded flowof fluid pressure through the coupling to permit emcient control of theservice brakes on the trailer.

It may be desired, however, to employ this coupling assembly in theemergency line as well, and, although it might appear that themechanical operation lof the valve would be sumcient for all needs, itwill be understood that, if the valves were mechanically operated only,separation of the coupling parts in the emergency line would result inimmediate closing of the valves under the action of the spring 62,'withthe result that the drop in pressure in the emergency line 25 of thetrailer would be insumcient to cause operation of the valve mechanism 24to eil'ect an emergency application of the trailer brakes.

to maintain the valve 80 in open position until .i

the pressure in the trailer emergency line drops below a predeterminedvalue,'it will be apparent that the valve in the coupling memberattached to the trailer will remain open. until a sufficient pressurereduction has occurred in the conduit 25 to eiIect an emergencyapplication` of the trailer brakes. It will also be understood in thisconnection that a coupling member of the type shown in Fig. 3 may becombined with a coupling member of the type shown in Fig. 2 or that thepressure responsive member may be omitted in one of the couplingmembers, as, for example, in the coupling member attached to the hose Ilin the emergency line of the tractor, without departing in any way fromthe spirit of the invention. It will also be apparent that the omissionof the pressure responsive member in the coupling portion 39 of Fig. 1will cause the valve 60 to close immediately on separation of thecoucorporated, will permit the escape of fluid pres.

sure to effect a reduction in the pressure in line 25 with a resultantemergency application of the trailer brakes.

Fig. 4 shows a somewhat simplified form of construction combining someof the advantages of the structures illustratedv in Figs. 2 and 3,mechanical and fluid pressure actuation of the valves being accomplishedwith the elimination of a considerable number of actuating parts. Withparticular reference to Fig. 4 it will be noted that a casing 50 isprovided for each half of the coupling, this casing being provided witha chamber 54 having an outlet port 55, together with a resilient sealinggasket `56. A valve 60 is also provided in each portion of the couplingfor normally closing the tapered bore in the gasket, the valve beingurged to closing position by means of a spring 62 interposed between thevalve and a cover 63 carried by the casing. A pressure responsivediaphragm 65 is clamped between the casing and the cover and isoperatively attached to the valve member 60. In order that mechanicalactuation of the valve may take place on joining of the couplingmembers, the lower end of thev upper valve is provided with a roundedprojection 90 which extends below the face of the resilient sealinggasket 56 when the valve is in closed position. Since this roundedprojection is carried by both the upper and lower valves, it

will be readily understood that on Joining of the coupling members,these projections will engage, with the result that the upper valve willbe moved in an upward direction against the tension of the spring 62while the lower valve will be moved in a downward direction, thus movingboth valves out of engagement with the tapered bores oi the resilientsealing gaskets and permitting the unrestricted passage of fluidpressure from oneportion of the coupling to the other. In the event theparts of the coupling device are separated, it will be apparent that asheretofore described in connection with other embodiments oftheinvention, the valveswill be maintained in open position by the actionof fluid pressure on the `closed and the entrance of dirt and otherforeign matter into the interior of the couplings which might be carriedto the control valves of the braking system is effectively prevented.

It will be seen from theforegoing description and from a study of thedrawing that coupling v for the most ei'llcient operation of the brakediaphragms 65 until the pressure has dropped to system` under al1operating conditions.

While several modifications of the invention have been described andillustrated, it is to be expressly understood that the invention is inno way limited thereby and that various changes and modiilcations may bemade therein without departing from the scope of the invention, for thelimits of which reference must be had to the appended claims.

What is claimed is:

1. Coupling means for vehicle carried fluid pressure braking systems ofthe type including an emergency line on each vehicle comprising portedcoupling means associated with each line, means for normally closingsaid ports, means op erable on connection of said coupling means foractuating said closure means to open said ports. and means carried bysaid closure means and responsive to the pressure in said lines foractuating said closure means to maintain said ports in open positionregardless of the action of said ilrst named actuating means.

2. The combination with a vehicle carried fluid pressure braking systemof the type including a fluid pressure brake control line carried byeach vehicle, of means for coupling said control lines including acoupling member associated with each line, a port in each member adaptedon coupling thereof to register with the port in the other member, meansfor normally closing the port in each of said coupling membrs, meansoperable on' engagement f said coupling members for moving said closuremeans to open said ports, and means carried by said closure means andoperable in response to a predetermined pressure in said lines foractuating the corresponding closure means to maintain said ports in openposition.

3. 'I'he combination with a iluid pressure brake system for a tractorand trailer of the type each having a service line and an emergency lineadapted to be connected for controlling the traily y thereof with thetractor carried coupling for establishing a connection therebetween, andported coupling means carried respectively by the tractor and traileremergency lines, the tractor carried coupling means having valvularmeans actuated in response to the coupling operation for opening theport thereof and the trailer carried coupling means having valvularmeans operable in response to variations of fluid pressure in thetrailer carried emergency line for maintaining vthe ports thereof inopen position when the pressure in said trailer carried emergency lineexceeds va predetermined value, whereby on separation of the vehiclesand disconnection of the service and emergncy couplings, the escape offluid pressure from the tractor carried service and emergency lines isautomatically prevented and the escape of iiuid pressurefrom the trailercarried emergency line is permitted.

4. A detachable coupling device for connecting a pair of fluid pressurelines including a coupling member associated with each line, an outletport in each of said coupling members, means associated with each ofsaid members for normally closing said ports, means actuated in responseto engagement of said couplings for moving said closure members to portopening position, and a single means carried by said closure means andresponsive to the pressure in said conduits for actuating said closuremembers and maintaining the latter in port opening position when thepressure in said conduits exceeds a predetermined l irrespective of theaction of said pressure revalue regardless of the operation of saidfirst named closure actuating means,

5. Means for coupling a pair of fluid pressure conduits including acoupling member associated with each conduit and adapted to be connectedwith the corresponding coupling member attached to the other conduit,and each of said members including exterior ports, including a closuremember normally closing said ports and associated with each couplingmember, mechanically operable means operable on coupling of the membersfor moving one of said closure members to port opening position, and uidpressure responsive means associated with the other coupling member andadapted to move the closure member thereof to port opening positionwheneverl the pressure in the second named conduit exceeds apredetermined value. f

6. A coupling member for a fluid pressure conduit adapted to beconnected with a corresponding coupling member on another fluid pressureconduit having an outlet port, valvular means for vnormally closing saidport, a pressure responsive member associated with said valvular meansfor moving said valvular means to port opening position when thepressure in said conduit exceeds a predetermined value, and meansactuated on coupling of said member to the corresponding coupling memberfor positively mov; ing said valvular means-to port opening positionsponsive means.

7. A detachable coupling member for uid pressure conduits comprising acasing having an outlet chamber and an outlet port associated therewith,valvular means for controlling the opening and closing of said outletport, resilient means interposed between the casing and said valvularmeans for normally maintaining said valvular means in port closingposition, a pres-y sure responsive member positioned in such casing anddividing said casing into outlet and atmospheric chambers, means forconnecting said pressure responsive member `with said valvular means foractuating the valvular means to port opening position in response to anincrease in pressure in said outlet chamber, a port in the wall of thecasing for connecting the atmos. pheric chamber with atmosphere, andmeans associated with said port and connected to and movable with saidvalvular means for preventing clogging oi said port by foreignsubstances.

8. A coupling device for a pair of fluid pressure lines comprising apair of detachable coupling members connected thereto, each of saidcoupling members having -a chamber formed therein, a pressure responsivemember carried by the casing and dividing said chamber into outlet andatmospheric chambers, an outlet port in said outlet chamber adapted toregister with the corresponding port in the other coupling member onengagement thereof, a iiexible sealing gasket associated with saidoutlet port and having a bore therethrough, valvular means carried bythe housing and normally positioned with relation to said gasket toclose the bore therethrough, resilient means interposed between saidvalvular means and casing for maintaining the valvular means in saidposition, means for actuating said valvular means and operable onjoining of said coupling members for moving said valvular means awayfrom said sealing gasket to permit the passage of iluid therethrough,and means connecting said pressure responsive means with said valvularmeans whereby the pressure in said outlet chamber actuates said pressureresponsive means to maintain said valvular means in said last namedposition.

. WILFRED A. EATON. ROGER H. CASLER.

